I would really not use a 3rd party tool to install iodéOS on a OnePlus. It is then just one more layer of obfuscation that could lead to a brick. Our graphical installer is the easy way, our manual process is also the easy way (using a script). Why is another tool needed?
But to what Vendor Security Patch Level is incorporated, how to confirm it, etc. I give some explanation and details in the other thread you started